Normal sudoku rules apply. All lines are both 'German Whispers' and Region Sum Lines! Digits on Region Sum Lines have an equal sum within each 3x3 box the line passes through. (Eg r6c6 = r5c7 + r4c7 = r7c5 + r7c4 = r8c3 + r9c2). Adjacent digits on German Whispers lines must have a difference of at least 5. In this puzzle, all lines must satisfy BOTH properties.